Difference between 185/70R-14 and 195/70R-14

[mlaw7]

I hope this doesn't cover ground already covered elsewhere. I did search through the forums but didn't see this exact question, so here goes.

I'm looking at a new set of tires for one of my '78 coupes.

Both have the stock 14" steel wheels. I've been pretty happy with the set of Yokohama Avid tires I have on the other '78, which I believe are 185/70R-14.

I know very little about tire design, etc. and am wondering what the difference would be if I used 195/70R-14's on this one. Is one "better" than the other for a stock 280Z as far as performance, handling, etc?

These would be used for normal everyday driving as well as the occasional high-speed zips around curves and winding country roads.

Thoughts?

[Gary in NJ]

195/70-14 is the stock size. I would choose that size over the 185/70's. They would give a better ride and the spedo would be more accurate.

[jaltman]

and... Just for future reference.... 195 is the width of the tire in millimeters. 70 is the aspect ratio or profile and means the sidewalls are 70% of the width, and the diameter is 14 inches. The 195/70-14 is 10 mm wider and 7 mm taller in the sidewall than the 185/70-14.

[5thhorsemann]

Fat tires rule!!!

[5thhorsemann]

Fyi compound is as, if not more, important than size when it comes to handeling. Just a thought.

[Gary in NJ]

195/70-14 is the stock size. I would choose that size over the 185/70's. They would give a better ride and the spedo would be more accurate.

Of course I should point out that "they would give a better ride" refers to tires of the same brand and model. Side walls vary from different manufacturers. But as a general rule of thumb, a 70 series tire will be more "compliant" then a 60 series.

Also 7mm may seem insignificant, but it's actually double that figure (think of it as 7mm above the rim and 7mm below the rim). 14mm in total is about 9/16 of an inch in overall height, or 18 feet of rolling distance resulting in a speedo error of 2.2%.

Yes, I AM a tire nerd.

[mlaw7]

Thanks everyone for the great info!

I checked last night and the Yokohamas I have now are in fact 195/70-14. As both of my '78's are 100% stock, I think I'll stick with those.

Another question:

Would you recommend 32 psi for this size and application?

[Arne]

Yes, I AM a tire nerd.

That makes two of us. (25 years in the business will do that to a person.) FWIW, I agree with pretty much everything posted here.

[Gary in NJ]

The recommended range is 28-32psi. I like the higher value because the steering is noticeably lighter at parking-lot speeds and more "nimble" at higher speeds.

[mlaw7]

Here's one for you tire gurus!

What does the "R" mean, for example in size 195/70R-14? Is it some kind of performance rating? Is there one that's better suited for Z cars than others?

Thanks again!

[Arne]

Radial

As opposed to:

Diagonal (bias)

or

Belted (bias belted)

[EScanlon]

R denotes RADIAL tires.

One note, the original tire specification was 175HR14 or 175SR14 or 6.45H14.4-PR if the owner's manual and Consumer Information pamphlet I have for the 71/72 are to be believed.

Edit: this is for the 240 not the 280

E

Edited November 11, 2010 by EScanlon